GB564827A - Process of preparing a dibenzopyran derivative having marihuana activity - Google Patents

Abstract

Dibenzopyran derivatives possessing marihuana activity are prepared by condensing pulegone with a 1 : 3-dihydroxy-5-R1-benzene under such conditions of time of refluxing and/or amount of condensing agent as to result in an optically active derivative. R1 is either hydrogen or an alkyl group with 1-10 carbon atoms. The preferred condensing agent is phosphorus oxychloride. The 1 : 3-dihydroxy-5-alkyl-benzenes may be prepared as described by Suter and Weston J. Am. Chem. Soc., Vol. 61, page 232. In examples: (1) Pulegone is condensed with orcinol in the presence of phosphorus oxychloride in benzene solution to give an optically active product. Variation in the amount of phosphorus oxychloride results in a variation of the optical activity of the product. (2) Pulegone is condensed with olivetol in the presence of phosphorus oxychloride in benzene solution and worked up to give an optically active tetrahydro-cannabinol which is an isomer of the compound obtained by the process of Specification 558,554. As in example (1), the optical activity of the product varies according to the amount of phosphorus oxychloride used. (3) Pulegone is condensed with 1 : 3-dihydroxy-5-n-butyl benzene as in example (1) to give-1-hydroxy-3-n-butyl-6 : 6 : 9-trimethyl-7-8-9-10-tetrahydro-6-dibenzopyran. (4) Pulegone is condensed with 1 : 3-dihydroxy-5-n-hexyl - 6 : 6 : 9-trimethyl-7-8-9-10-tetrahydro - 6 - dibenzopyran. The corresponding compounds may be obtained by using the appropriate iso-amyl, heptyl or octyl derivatives of 1 : 3-dihydroxy benzene.